Traffic-related particle emissions that result not from exhaust gas but from abrasion of brakes, tires, clutches, road surface etc. and from resuspension of road dust make a considerable contribution to air pollution. It is expected that exhaust gas particle emissions will decrease owing to increasingly stringent limit values, but the other traffic-related particle emissions will increase owing to greater traffic volumes, and could become the focus of future regulations. Based on data from the German Federal Environmental Agency, it can be expected that, in the year 2020, exhaust gas particle emissions will still account for approximately 18% of all traffic-related fine dust emissions, wherein the expression “fine dust” refers to particles with aerodynamic diameters of less than 10 μm. The remaining 82% are emissions caused not by exhaust gas but by wear. This illustrates the increasing significance of particle emissions not caused by exhaust gas.
For the reduction of brake dust emissions in particular, techniques such as for example shields, blowers and dust collectors are known.
DE 10 329 961 A1 discloses a motor vehicle having an integrated fine dust extraction device for vehicles that filters and collects fine dusts out of the ambient air for scientific tests, which fine dusts can also be analyzed by way of an aerosol spectrometer as a dust measurement unit even during the collection process, wherein the measured data can be transmitted by radio.
Also, motor vehicles have already been proposed by means of which it is sought to remove fine dusts from the ambient air during travel.
For example, DE 20 2006 019 335 U1 discloses a fine-dust extraction device for vehicles, by means of which fine dusts can be removed from the fresh air supplied to the vehicle interior compartment, but by means of which it is also possible for the fine dust content in the ambient air to be reduced in order to comply with legally prescribed fine dust limit values.
DE 20 2006 004 522 U1 discloses a fine dust filter that operates with electrical or magnetic separation and is arranged between an air inlet grille and radiators of a vehicle for the purposes of removing fine dusts from the ambient air flowing through there, even fine dusts that have been emitted or resuspended by other vehicles.
DE 20 2005 005 673 U1 discloses an outside-air filter for motor vehicles, which outside-air filter is mounted below a bumper and serves for the general reduction of air pollution.
Such systems would be capable of effectively reducing fine dust in the environment only if they were installed in a very large number of vehicles, and the outlay for cleaning the numerous filters and for the disposal of the collected dusts would be extreme, especially as relatively coarse dusts that are not actually harmful would also be collected, and the filters would quickly become full.
DE 10 2009 054 194 A discloses a vehicle having a head-up display and having a camera introduced into the beam path thereof, and, from the image data of the camera, it is also possible for rain or dirt on the windshield to be detected.
JP H09 242 500 A discloses an environmental measurement vehicle having a dust concentration sensor arranged on the roof.